1. Field of the invention
The present invention relates to a zigzag sewing machine. More particularly, the present invention relates to a zigzag sewing machine that can successively form a plurality of patterns by repeatedly sewing a preselected pattern. Related art
In a conventional zigzag sewing machine, stitch data corresponding to predetermined patterns is stored in a memory. Under control of a microcomputer, the stitch data is read from the memory and a control signal is sent to a stitch forming mechanism, thereby controlling the operation of a needle and a feed dog. In this way, a pattern is automatically formed on a fabric in repetition.
However, when a plurality of patterns are successively sewn, fixing stitches normally must be formed at the beginning and the end of each pattern to prevent thread from loosening. Forming three stitches at the beginning and the end of each pattern is one such method of preventing thread loosening. Forming fixing stitches, however, must have been manually done, making pattern sewing time-consuming and tiresome. Fixing stitches must have been formed manually because fixing stitch data could not be included in pattern forming data. More particularly, if fixing stitches at the beginning and the end of each pattern is included in stitch forming data, the fixing stitches formed at the end of one pattern coincide with the fixing stitches of the beginning of the next adjacent pattern. Therefore, two sets of fixing stitches are formed between adjacent patterns. This reduces the aesthetical value of the patterns and damages the fabric.